Conventionally, a liquid ejecting system provided with a liquid ejecting apparatus provided with a liquid ejecting unit for ejecting a liquid such as ink, and a liquid storing container for supplying a liquid to the liquid ejecting unit is used. Patent Literature 1 discloses an example of a liquid ejecting system of this type. In Patent Literature 1, a tank case that houses an ink tank is mounted on a side face of an inkjet printer, which is an example of a liquid ejecting apparatus. A checking window is provided in a side face of the tank case (the side face on the side opposite to the side on which the inkjet printer is arranged). When refilling the ink tank with ink, the tank case is removed from the inkjet printer, and the tank unit is turned over so as to be in a refill orientation in which an injection port of the ink tank is directed upward. After the ink is injected, the tank unit is returned to the original orientation and is mounted to the inkjet printer.